I checked my ESXI's and they do not have this update installed.
I'm just scared to manually update, because it says that impact will be a reboot.
Although I have vsphere HA, do I need to scare to do any reboot to the esxi's?
Put your ESXi Host into maintenance mode before you apply updates, that way you are sure your production will not be harmed. After the ESXi Hosts has rebooted you can take it out of maintenance mode again.
When everything is ok you can proceed with the other hosts in your cluster...